Manufacture of blocks, plates, and other articles for use in road-making, building, and for similar purposes.



To all whom it may concern:

swan STATES PATENT canton.

HAROLD MILLS CLIFFORD, OI WESTMINSTER; ENGLAND, ASSIGNOR TO CORK ASPHALT LIMITED, OE LONBON, ENGLAND, A COMPANY.

MANUFACTURE or BLocKs, PLATEs, AND o'rmza ARTICLES son USE n ROAD- MAKING, BUILDING, AND FOR SIMILAR PURPOSES.

Specification of Letters Patent.

Patented April 6, 1909.

' Application filed October 15, 1906. Serial No. 339,146 I Be it known that l[, HAROLD MILLS CLIF- rono, a subject of the King of England, .re-' siding at 25 Victoria street, in the city of Westminster, England, gentleman, have invented certain new and useful Improvements in the Manufacture of Blocks, Plates, and other Articles for use in Road-Making, Building, and for Similar Purposes, (for which 1 have applied for a patent in England, and which application is dated Sepfollowing is a specification.

tember 27, 1906, No. 21,437,) of which the This inventionrelates to improvements in the manufacture of blocks or plates for use in road-making or building, as brake blocks- (for use on vehicles for instance), in making conduits for electric wires and for numerous other purposes: v

The use of bitumen mixed with various other substancs-cork and so forth-in such manufacture is well known, but the process hereinafter described yields a material that is far superior to anything yet produced from bituminous mixtures.

In making bituminous blocks, plates, and so forth by the known methods, material has been produced which, though possessing many desirable qualities, nevertheless wasv either not perfectly homogeneous or too loose ,in structure, or too costly. Some methods hitherto known produced materials which it was diflicult' or impossible to prepare at a factory and'then totransport in a condition for immediate use, without difficultor tedious manipulation at the place where the material is ultimately to be employed. The present process however yields a material that is formed into blocks, plates,

sheets, or into other convenient articles at the factory. The goods so made can be transported without any further preparation. Theywill be of great density, comparatively speaking light; impervious to moisture and not readily affected by atmospheric or other injurious influences.

' The essential featuresof the process are 1. The materials are mixed while'colda 2. The mixed materials are heated to the temperatures hereinafter stated, and molded.

in'that state. They then become a plastic mass in which the bitumen causes the whole tocohere. 3."= The"freshly-molded, heated mass is pressure has been applied. The mold b'ein subjected tohigh pressure in the molds and according to the nature of the articles made.

The materials used are: for every hundred parts by weightparts of cork. 15 parts of sawdust. 70 parts of hard, brittle, refined bitumen (asphaltum containing little or no bituminous oil. T ese proportions may be varied, but any substantial departure therefrom is undesirable. For the cork'or art or sawdust, other materials maybe in wholly substituted, such as cocoanut ber.

The cork may be waste cork; the sawdust and cork should be clean, i. e.free from any notable admixture of sand, ,dirt, or other foreign substances. The cork is ground so as to passthrough a sieve,- preferably of 2 to 3'millimeter mesh, and mixed with the sawdustL The bitumen anysuitable crushing, disintegrat1ng,-; or. grinding machine rejgluced to ,granule s fthat will pass ,throughfi sieve of preferably 3 to 6' millimeter mesh. The materials: are then thoroughly-mixed while cold andin the proportions hereinabove named. are should be taken t'o mixwell, so as v,Qobtain a uniform distribution of the. component .parts throughout the mixture. Thls mixture is now heated with constant. stirring, say in open steamjacketed troughs fitted with stirrers..; The temperaturemust not bev be low 130 0., but it is preferable to heat from about 140 to 150 C. When by these means a thoroughly plastic mass, uniformin composition throughout, has been obtained, the temperature is allowed to fall to 110, to 125 0., and the mass is then filled into molds. In the moldsv it is subjected to a pressure of 100 to 120 kilograms per square centimeter for ordinary road paving blocks,

the temperature being maintained until the closed under pressure, there is no nee further to maintain the heat. a The pressure however has to be maintained until the the pressure is mamtained fro n the moment block, or the like, has thoroughly cooled. The pressure is then removed, the article is taken out of the mold, and will be found to be light, strong, and capable of very great resistance to Wear as Well as to atmospheric influences, putrefaction, and so on.

The temperatures above given should be closely adhered to, as they will free the ma- -terial from undesirable volatile constitucohesion of the material, vwhile an undue preponderance of cork will render the surface absorbent when wear begins to affect it,

Claims. 1. A process for manufacturing blocks, plates and other articles consisting in mixing in the cold state bitumen cork and saW- dust, then making the mixture plastic and at the same time freeing it from volatile oil by heating to at least 130 C. with constant stirring and molding the resulting plastic mass.

2A process for manufacturing blocks,

plates and other articlesconsistingin mixmg bitumen .in the cold state with granular material also in the cold state, heating the mixture, compressing the hot mixture in molds and cooling while the pressure is maintained. I

A process for manufacturing blocks, plates and other articles consisting in mixing in the cold state bitumen with cork and sawdust then making the mixture plastic and at the same time freeing it from volatile oil by heating to at least 130 C. with constant stirring, compressing the hot oilfree mixture in molds and cooling while the pressure is maintained.

4. A new composition of matter consisting of bitumen made oil free by heat and partly penetrating the granular material and cementing the granules together.

5. A new composition of matter for use in road making, building and for other technical purposes consisting of 70 parts by weight of. oil-free bitumen 15 parts by weight of granulated cork and 15 parts by weight of sawdust partly penetrated and cemented together by the bitumen.

In testimony whereof I have hereunto set my hand in the presence of two witnesses.

HAROLD MILLS CLIFFORD.

VVitnesses' G. F. WARREN, BERNHARD DUKES. 

